title: Assessing the performance of the EQ-VAS in the NHS PROMs programme.
abstract: OBJECTIVE
  The study aims to increase knowledge about the performance of the EuroQol-visual analogue scales (EQ-VAS) in the UK NHS patient-reported outcome measures (PROMs) programme, which covers groin hernia, hip and knee replacement and varicose vein surgery, and make suggestions for improved collection, coding and analysis of data.
  
  
  METHODS
  Four hundred scanned images of matched before-and-after EQ-VAS PROMs responses were selected at random. These were classified according to the different ways in which they were completed. Patient-level PROMs programme data linked to Hospital Episode Statistics for all patients from April 2009 to February 2011 were used to analyse the relationship between the EQ-VAS and the EQ-5D profile, index-weighted profile and condition-specific instruments. The linked PROMs and HES data comprise 331,951 anonymised patient records.
  
  
  RESULTS
  A large majority (95 %) of EQ-VAS responses were completed in an unambiguous way, but only a minority (45 %) conformed strictly to the instructions given, posing challenges for data coding. The EQ-VAS data have a predictable and consistent relationship with the EQ-5D profile, although the correlations between the EQ-VAS and other measures of patient-reported health, both before and after surgery and in the change between them, are weak.
  
  
  CONCLUSIONS
  EQ-VAS data might be improved by providing better guidance on collection and coding. It is argued that the observed differences in results from EQ-VAS and other measures of health reflect the fact that it measures a broader underlying construct of health, arguably providing a means of summarising overall health that is closer to the patient's perspective.
authors.affiliation: Office of Health Economics, 7th Floor, Southside, 105 Victoria Street, London, SW1E 6QT, UK, yfeng@ohe.org.
authors.forename: Yan
authors.initials: Y
authors.lastname: Feng
authors.forename: David
authors.initials: D
authors.lastname: Parkin
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Devlin
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000523:psychology / Q000534:rehabilitation; D019645:Arthroplasty, Replacement, Knee / Q000523:psychology / Q000534:rehabilitation; D006552:Hernia, Inguinal / Q000523:psychology / Q000534:rehabilitation; D006801:Humans; D009313:National Health Programs; D010147:Pain Measurement; D063868:Patient Outcome Assessment; D015397:Program Evaluation; D019984:Quality Indicators, Health Care; D011788:Quality of Life; D013222:State Medicine; D011795:Surveys and Questionnaires; D006113:United Kingdom; D064232:Visual Analog Scale